Heretofore, the feeding of stock into an automatic machine, such as a lathe or screw machine, is an extremely noisy operation, particularly where the stock is being fed into the machine at a rapid rate of speed and the rotatable indexing head creates a great amount of clatter so that a shop equipped with such machines is extremely noisy. Several attempts heretofore have been made to reduce the noise associated with such operations such as providing insulating material about the mechanism in which the bars are mounted, or by mounting resilient plastic sleeves about the barstock so that the barstock will feed along the resilient sleeves with a minimum of noise. Barstock sometimes has a rough outer surface such as spurs and this tends to wear the plastic sleeves and the like through abrasion which necessitates the replacement of such sleeves quite often.
Sound insulating material employed heretofore may consist of packing such as mineral wool, cotton, felt or the like packed within a shell through which the barstock is fed. These arrangements have been satisfactory in the reduction of noise but are costly in application.